Evaluation of hot-pressed hydroxyapatite/poly-L-lactide composite biomaterial characteristics

Hydroxyapatite/poly-L-lactide (HAp/PLLA) is a ceramic/polymer composite, whose application as a resorbable biomaterial for the substitution and repair of hard bone tissue is widely promising in orthopedic, oral, maxillofacial, and reconstructive surgery. Hot processing is a necessary step for obtaining HAp/PLLA composite blocks with mechanical properties similar to those of bones. In this article, the changes in structure and physicochemical properties of HAp/PLLA composite, hot pressed for different pressing times (5, 15, 30, 45, and 60 min), were studied. Because the morphology of HAp/PLLA composite biomaterial is very sensitive to this procedure, its surface microstructure was analyzed by scanning electron microscopy (SEM) coupled with an energy-dispersive X-ray (EDX) detector system. Structural changes occurring in the material, mostly changes in crystallinity of PLLA, were studied by wide-angle X-ray structural analyses (WAXS) and infrared (FTIR) spectroscopy. Using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and gel permeation chromatography (GPC), the influence of hot pressing on the properties, crystallization kinetics, and decomposition of HAp/PLLA composite biomaterial was analyzed.     

Influence of local inflammation of the peritoneal membrane on diuresis and residual renal function in patients treated with peritoneal dialysis

The aim of this study was to investigate the connection between local inflammation of the peritoneal membrane and diuresis, as well as the residual renal function (RRF) in patients treated with continuous ambulatory peritoneal dialysis (CAPD). Twenty patients treated with CAPD participated in this cross-sectional study. To determine the influence of local inflammation of the peritoneal membrane, effluent interleukin-6 (IL-6) and soluble interleukin-6 receptor (sIL-6R) levels were measured. The level of IL-6, in the group as a whole, was significantly higher in effluent (7.87 pg/mL) than in serum (1.29 pg/mL). There was a significant correlation between effluent and serum IL-6 (r = 0.608; P = 0.002). There was also a significant relationship between effluent and serum IL-6 and duration of CAPD treatment, respectively (r = 0.577; P = 0.004; r = 0.528; P = 0.008). Further, there was a significant negative correlation between effluent IL-6 and daily diuresis (r = −0.533; P = 0.008), but there was no significant correlation between effluent IL-6 and RRF (r = −0.339, P = 0.072). On the other hand, the concentrations of effluent IL-6 were significantly higher in patients with RRF <2 mL/min than in those with RRF ≥2 mL/min (P = 0.039). In conclusion, local inflammation has a significant impact on the amount of diuresis and probably on RRF in patients on CAPD.     

Acute leg compartment syndrome after exertion

A case of a 22-year old soldier, with a history of pain in the leg during heavy exercise, which desisted at rest, was presented. One day before admission, the patient had felt an extreme exertion-induced pain in his right leg which had not lessenned at rest. At the same time, the patient noticed persistent severe leg edema. On physical examination, the intracompartmental pressure was 62 mmHg (> 30 mmHg). The patient was urgently operated on, and fasciotomy according to Mubarak was used. At second surgery, the debridement of the muscles of the posterior group of the leg, and the evacuation of hemathoma from the anterior and lateral group of the right leg muscles were perfomed. Postoperative recovery was uneventful. Fasciotomy wounds were closed within 14 days of the surgery. The complete physical treatment was done. Follow-up examinations 1, 3, and 6 months afterwards were satisfactory. The soldier completed his compulsory military service without any sequelae. Laboratory results were normal. Overlooked, unrecognized or surgically untreated compartment syndrome can cause severe damage, including even the loss of the extremity.     

Role of mitotic, pro-apoptotic and anti-apoptotic factors in human kidney development

The expression pattern of mitotic Ki-67 and anti-apoptotic bcl-2 proteins, as well as apoptotic caspase-3 and p53 proteins, were investigated in the human mesonephros and metanephros of 5–9 week-old human conceptuses. Apoptotic cells were additionally detected using the terminal deoxynucleotidyl transferase (TdT) nick-end labelling (TUNEL) method. Between the 5th and 7th developmental weeks Ki-67, caspase-3 and TUNEL-positive cells characterized all mesonephric structures, indicating importance of cell proliferation in the growth of the mesonephros and role of apoptosis in nephrogenesis. From the 7th week on, p53 and bcl-2 positive cells appeared in the mesonephros as well. Regressive changes in the mesonephros could be regulated by activation of p53, while bcl-2 could contribute to selective survival of some tubules giving rise to adult structures. In the early human metanephros (5–7 weeks), Ki-67 positive cells characterized all metanephric structures, indicating a role of cell proliferation in branching of the ureteric bud and in nephron formation. During the same period bcl-2, caspase-3 and TUNEL-positive cells were found only in the metanephric mesenchyme and nephrons. Bcl-2 protein probably protected nephrons from apoptosis, while caspase-3 protein controlled cell death in the mesenchyme. At later stages (7–9-weeks), appearance of p53-expressing cells could participate in further morphogenesis of the metanephric collecting system. The factors investigated had a spatially and temporally restricted pattern of appearance in developing kidneys. Changes in that pattern might lead to serious disturbances of kidney formation and function in early childhood.     

Popliteal traumatic arteriovenous fistulas

BACKGROUND: The purpose of this report is to analyze the clinical presentation, diagnosis, and outcome of surgical treatment in patients with popliteal arteriovenous fistulas (AVFs) in order to make trauma surgeons aware of the various issues patients with popliteal AVFs might present. METHODS: From 1991 to 2000, 49 patients were treated for traumatic AVF. Among these patients, seven suffered from popliteal AVF of various durations. The patients were men and ranged in age from 17 to 27 years, with a mean age of 22.4 years. The time from injury to admission to our institutions varied from 5 days to 2 years. A diagnosis of popliteal AVF was made after clinical examinations revealed thrill and bruit over the injury sites. The diagnosis was confirmed in four of the patients after they underwent angiography. Patients with long-standing popliteal AVF underwent cardiology examinations to check for signs of heart failure. All patients with popliteal AVF received surgical treatment. Five patients had major blood vessels reconstructed, one patient had a minor blood vessel ligated, and another patient had a minor blood vessel reconstructed. RESULTS: Five of the seven patients experienced no postoperative difficulties. No serious heart failure occurred; however, there were signs of cardiac overload in three of the five patients. The two remaining patients of the seven underwent leg amputations. However, one of the two patients had a gangrenous foot at admission to our institution, and vascular reconstruction on the other patient was unsuccessful. For all seven patients, the average hospital stay in the vascular surgery department was 16.2 days and the follow-up ranged from 2 to 44 months, with a mean of 21.5 months. CONCLUSION: Trauma of the popliteal space requires special attention, since blood vessel injuries in that zone might result in serious complications. Popliteal traumatic AVFs result in a high rate of leg amputation and long-standing fistulas produce cardiac overload. The presence of thrill and bruit over the injury site should alert the examiner to consider the existence of AVF. Angiography is a reliable diagnostic tool, and should be used in all vitally stable patients. Surgical or nonsurgical closure of AVF will prevent local and systemic complications that might be irreversible in long-standing fistulas.     

Necrotizing fasciitis caused by group A streptococcus

The first case of the confirmed necrotizing fasciitis caused by Group A Streptococcus in Yugoslavia was presented. Male patient, aged 28, in good health, suddenly developed symptoms and signs of severe infective syndrome and intensive pain in the axillary region. Parenteral antibiotic, substitutional and supportive therapy was conducted along with the radical surgical excision of the necrotizing tissue. The patient did not develop streptococcal toxic shock syndrome thanks to the early established diagnosis and timely applied aggressive treatment. He was released from the hospital as completely cured two months after the admission.     

Recurrent episodes of focal cerebral ischemia in a female patient with mitral valve prolapse and migraine headache

Migraine is episodic, paroxysmal disorder where the headache represents the central symptom and is followed with different combinations of neurologic, gastrointestinal and vegetative changes. Not until the diagnostic procedures were developed, ischemic lesions were verified even in the patients with ordinary migraine. This is a report of a patient with migraine headache, followed twice by verified episodes of temporary ischemic attacks and verified focal ischemic lesion of cerebral parenchyma. The mitral valve prolapse was also detected. This all imposed the administration of combined prophylactic antimigrainous and anticoagulant therapy as an imperative because of the risk of the development of repeated ischemia of cerebral tissue. This association also confirmed an opinion that migraine is a wider disorder with the dominant dysfunction of limbic system.